Did he think the police needed more than 28 days to question terrorist suspects?

"I want to have absolute evidence that we actually need longer than 28 days," the former first sea lord told the BBC.

"I want to be totally convinced because I am not going to go and push for something that actually affects the liberty of the individual unless there is a real necessity for it. I still need to be fully convinced that we absolutely need more than 28 days and I also need to be convinced what is the best way of doing that."

But less than an hour later, following a breakfast with the prime minister, West had changed tack.

Sounding just as certain as he had barely 45 minutes before, he declared he was "personally convinced" that the 28-day limit needed extending.

"I personally, absolutely believe that within the next two or three years we will require more than that for one of those complex plots. So I am convinced that is the case."

Later, he added: "I am quite clear that the greater complexities of terrorist plots will mean that we will need the power to detain certain individuals for more than 28 days."

Exactly what was said between West and Brown over orange juice and yoghurt at Downing Street was uncertain last night, but it led to the admiral executing a perfect U-turn at full speed.

As the man who will have to nurse any counter-terrorism legislation through a sceptical House of Lords next year, his frank admission that he was not yet sold on the need to extend 28-day detention threatened to sink one of Brown's key policies.

Unsurprisingly, the prime minister's spokesman found some difficulties explaining the logic behind the admiral's apparent change of course.

The official record of his briefing to political reporters reads: "Asked to what extent the prime minister played a role in getting Lord West to change his mind, the PMS replied that he was not sure that Lord West had changed his mind."

He added: "Lord West has made his position quite clear, the words speak for themselves."

As the morning wore on, West, one of the four ministers drafted into government from outside party politics, decided the best tactic was to plead naivety, an innocent in the Westminster bearpit.

"Being a simple sailor not a politician maybe I didn't choose my words well ... Maybe my choice of words wasn't very clever," said the man who has been chief of defence intelligence, commanded three frigates, and is the holder of a distinguished service cross.

The admiral's explanation was not enough for the Conservative leader, David Cameron, who duly accused Brown of undermining the admiral's credibility and leaning on his security minister to change his view.

He accused Brown of being "not so much concerned with the evidence as with the politics".

Downing Street fired back, unearthing previous remarks from West suggesting he did support an extension. However, on closer inspection, even some of these quotes revealed an ambivalence.

In all this West's true views on detention now remain truly submerged.

There is some fragmentary evidence that he had indeed not meant to break ranks in his initial interview.

Shortlly after leaving the Today studio, West heard the BBC 8.30am news summary reporting him saying he wanted to have evidence before he could be convinced of the need to go beyond 28 days.

He then turned to his Home Office minder and said to him: "Why are they saying that about me?".